Power factor is a ratio of real power to apparent power. Real power measures the ability of a network load to perform work in a particular time, and is associated with power consumption by a resistive load. Apparent power is the product of voltage and current, and may be equal to or greater than the real power due to an impedance of a reactive load. In a purely resistive circuit, voltage and current waveforms are in step, changing polarity at the same instant in each cycle. In such a circuit the power factor is one. In a circuit having reactive loads, such as a circuit having capacitive or inductive loads, there may be a time difference (a phase delay) between current and voltage waveforms of the alternating current power. In particular, the capacitive and/or inductive loads alternately store and release energy and may alter the phase between current and voltage. In such a circuit the power factor may be less than one. Because the stored energy returns to its source and is not available to do work at the load, a circuit with a lower power factor will receive higher currents for a given quantity of received real power than a circuit with a higher power factor. Accordingly, power lines may carry more current than necessary to provide power to portions of a power distribution network having reactive loads. The additional current may result in additional real power losses caused by the losses of the power transmission lines in conducting the additional current and may require the generating facility to produce more power.
It is undesirable for a power distribution network to have portions with a power factor that is substantially far from unity. Production of such excess power is inefficient and is inconsistent with policies of conserving energy and preserving environmental resources. Further, in order to distribute the increased apparent power, the utility may need to build additional infrastructure for networks beyond the networks required for distribution of real power. Further, consumer utility meters typically measure only real power and consumers are charged for real power consumption. However, the costs of delivering power determine power rates. Thus, power utility rates may increase to reflect the utility company's cost of delivering the higher apparent power. Accordingly, it is desirable to measure and correct the power factor of a power distribution system to thereby enable the power distribution system to operate in a more efficient manner. These and other advantages may be provided by one or more embodiments of the other present invention.